title: Tip110 interacts with YB-1 and regulates each other's function.
abstract: BACKGROUND
  Tip110 plays important roles in tumor immunobiology, pre-mRNA splicing, expression regulation of viral and host genes, and possibly protein turnover. It is clear that our understanding of Tip110 biological function remains incomplete.
  
  
  RESULTS
  Herein, we employed an immunoaffinity-based enrichment approach combined with protein mass spectrometry and attempted to identify Tip110-interacting cellular proteins. A total of 13 major proteins were identified to be complexed with Tip110. Among them was Y-box binding protein 1 (YB-1). The interaction of Tip110 with YB-1 was further dissected and confirmed to be specific and involve the N-terminal of both Tip110 and YB-1 proteins. A HIV-1 LTR promoter-driven reporter gene assay and a CD44 minigene in vivo splicing assay were chosen to evaluate the functional relevance of the Tip110/YB-1 interaction. We showed that YB-1 potentiates the Tip110/Tat-mediated transactivation of the HIV-1 LTR promoter while Tip110 promotes the inclusion of the exon 5 in CD44 minigene alternative splicing.
  
  
  CONCLUSIONS
  Tip110 and YB-1 interact to form a complex and mutually regulate each other's biological functions.
authors.affiliation: University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
authors.forename: Khalid Amine
authors.initials: KA
authors.lastname: Timani
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Johnny J
authors.initials: JJ
authors.lastname: He
mesh_terms: D020816:Amino Acid Motifs; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D016325:HIV Long Terminal Repeat; D006801:Humans; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D051840:Y-Box-Binding Protein 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D016601:RNA-Binding Proteins; C416530:SART3 protein, human; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D054322:tat Gene Products, Human Immunodeficiency Virus